Comorbidities in overweight children and adolescents: do we treat them effectively?

OBJECTIVE

The aim was to analyze the effectiveness of treatment concerning obesity-associated comorbidities in clinical practice.

METHODS

A total of 11,681 overweight children with ≥ 6-month follow-up treated at 175 centers specialized in pediatric obesity care in Central Europe were included in this analysis (mean body mass index (BMI) 29.0 ± 5.6 kg m(-)(2), standard deviation score body mass index (SDS-BMI) 2.48 ± 0.54, 45% boys, age 11.4 ± 2.8 years). The changes of weight status, blood pressure, fasting lipids and glucose, and oral glucose tolerance tests were documented by standardized prospective quality documentation software (APV).

RESULTS

After follow-up of in median 1.2 (interquartile range 0.9-2.2) years, a mean reduction of -0.15 SDS-BMI was achieved. The prevalence of prehypertension (37->33%) and hypertension (17->12%) decreased, while prevalences of triglycerides >150 mg dl(-1) (22->21%), low-density-lipoprotein-cholesterol >130 mg dl(-1) (15->14%), impaired fasting glucose (6->6%) and impaired glucose tolerance (9->8%) remained stable. Drug treatment according to cutoffs recommended in European obesity guidelines were not frequently indicated (hypertension: 10%; dyslipidemia: 1%, type 2 diabetes <1%). None of the children with dyslipidemia received lipid-lowering drugs and only 1.4% of the children with hypertension were treated with antihypertensive drugs.

CONCLUSIONS

Achieving sufficient weight loss to improve obesity associated comorbidities was difficult in clinical practice. Drug treatment of hypertension, dyslipidemia and type 2 diabetes was rarely performed even if it was indicated only in a minority of the overweight children. Future analyses should identify reasons for this insufficient drug treatment of comorbidities and analyze whether the benchmarking processes of APV improve medical care of childhood obesity.

[Long-term inpatient treatment of extreme juvenile obesity: an 18-month catamnestic study]

Eighteen months after completion of long-term treatment of 98 extremely overweight juveniles in the rehabilitation center Insula, this study revealed an improvement in the age-specific body mass index (BMI-SDS) in 55.1% of the cases, when all the non-responders (approx. 22%) were evaluated as failures. An improvement of at least 0.2 or 0.5 BMI SDS points was achieved in 41.8% and 21.4%, respectively.

Mutation screen of the brain derived neurotrophic factor gene (BDNF): identification of several genetic variants and association studies in patients with obesity, eating disorders, and attention-deficit/hyperactivity disorder

Several lines of evidence indicate an involvement of brain derived neurotrophic factor (BDNF) in body weight regulation and activity: heterozygous Bdnf knockout mice (Bdnf(+/-)) are hyperphagic, obese, and hyperactive; furthermore, central infusion of BDNF leads to severe, dose-dependent appetite suppression and weight loss in rats. We searched for the role of BDNF variants in obesity, eating disorders, and attention-deficit/hyperactivity disorder (ADHD). A mutation screen (SSCP and DHPLC) of the translated region of BDNF in 183 extremely obese children and adolescents and 187 underweight students was performed. Additionally, we genotyped two common polymorphisms (rs6265: p.V66M; c.-46C > T) in 118 patients with anorexia nervosa, 80 patients with bulimia nervosa, 88 patients with ADHD, and 96 normal weight controls. Three rare variants (c.5C > T: p.T2I; c.273G > A; c.*137A > G) and the known polymorphism (p.V66M) were identified. A role of the I2 allele in the etiology of obesity cannot be excluded. We found no association between p.V66M or the additionally genotyped variant c.-46C > T and obesity, ADHD or eating disorders. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299:1/suppmat/index.html.

No evidence for involvement of the promoter polymorphism -866 G/A of the UCP2 gene in childhood-onset obesity in humans

Recently, an association between obesity and the G-allele of the - 866 G/A polymorphism in the promoter region of uncoupling protein-2 gene (UCP2) was reported. Both allele frequencies and genotype distributions for this polymorphism differed between obese individuals and never-obese controls. We attempted to confirm this finding. Genotyping was performed by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). We analysed transmission disequilibrium of the (wild type) G-allele for 200 extremely obese children and adolescents from 93 concordant sib pair families using the pedigree disequilibrium test. Additionally, using a one-sided asymptotic Pearson's chi 2-test, we tested whether the G-allele occurs more frequently in 277 extremely obese children and adolescents (including the 93 index patients of the concordant sib pairs) than in 188 never-obese controls. The one-sided asymptotic Cochran Armitage trend test was used to determine differences in genotype frequencies between extremely obese and healthy underweight individuals. The PDT analysis revealed no evidence for transmission disequilibrium in obesity. Allele and genotype frequencies did not differ between the extremely obese and never-obese subjects. In conclusion, we cannot confirm the results of ) in our young sample.

No evidence for involvement of alleles of the 825-C/T polymorphism of the G-protein subunit beta 3 in body weight regulation

The 825-C/T polymorphism of the beta 3 subunit of the heterotrimeric G protein gene (GNB3) has been shown to be associated with essential hypertension in humans. Recently, it was also reported that the 825-T allele has a higher frequency in obese than non-obese hypertensives suggesting that the primary effect of this allele is on body weight. The association to hypertension might merely be a secondary effect of the higher weight of the respective allele carriers. To investigate an involvement of the 825-T allele in body weight regulation in young individuals, we evaluated allele frequencies in 440 extremely obese children and adolescents (82.9% had a body mass index [BMI] > or = 99th percentile), 51 obese students (BMI > or = 90th percentile), 110 normal weight students (BMI between 40th and 60th percentile) and 144 underweight students (BMI < or = 15th percentile). The study groups were genotyped by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). The one-sided Yates-corrected chi(2)-test and the Cochran-Armitage trend test for association were performed. Tests for association were negative. The 825-T allele frequencies were similar in the four study groups belonging to different weight ranges (extreme early onset obesity: 0.29; obesity: 0.28; normal weight: 0.35; underweight: 0.32). Similarly, genotype frequencies did not differ between the groups. We concluded that the 825-T allele of the GNB3 does not play a major role in weight regulation in German children, adolescents and young adults.

Systematic screening for mutations in the human necdin gene (NDN): identification of two naturally occurring polymorphisms and association analysis in body weight regulation

BACKGROUND

NDN, which codes for the human necdin protein, is a candidate gene for Prader-Willi syndrome (PWS). One feature of this neurogenetic disorder is hyperphagia resulting in extreme obesity observed later in development.

OBJECTIVE AND DESIGN

In this study we have used single-strand conformation polymorphism (SSCP) analysis to identify sequence variants at the human necdin gene. Furthermore we tested whether these variants were associated with obesity in extremely obese German children and adolescents.

RESULTS

Two gene variants could be identified: a g.1352T-->C polymorphism in the putative promotor region and a silent g.2311C-->T polymorphism in the coding region. Genotype and allele frequency distribution of both of the polymorphisms were not significantly different between lower and higher body mass index (BMI) subjects.

CONCLUSIONS

Hence, it is unlikely that these polymorphisms play a major role in the emergence of juvenile onset human obesity.

Efficacy of 'functional relaxation' in comparison to terbutaline and a 'placebo relaxation' method in patients with acute asthma. A randomized, prospective, placebo-controlled, crossover experimental investigation

BACKGROUND

'Functional relaxation' (FR) according to Marianne Fuchs is a body-oriented psychotherapy that involves teaching the patient a type of relaxation techniques aimed at maintaining equilibrium of the nervous system.

METHODS

In order to determine whether the practice of elementary parts of this therapy has an immediate beneficial effect on pulmonary function, a randomized, single-blind, prospective crossover study was done with 21 asthmatics with acute bronchoconstriction. On 3 consecutive days they were given either (1) a 5-min verbal standard instruction in elementary exercises of FR (eFR), which they were to practice during subsequent bodyplethysmographic measurement or (2) inhalative terbutaline (IT), a beta(2)-sympathomimetic drug, or (3) an unspecific 'placebo relaxation' technique (PRT), so that all subjects tried all 3 treatments in random order. Spirometric variables were assessed.

RESULTS

There was a significant decrease in specific airway resistance with eFR, which, though not as pronounced as with IT, was significantly greater than with PRT. This study shows that clinically relevant effects can be achieved for patients with asthma through mind-body interaction, which can be triggered by reproducible procedures.

CONCLUSION

Further development of the FR approach could lead to a nonpharmacological and effective supplementary treatment for asthma, which is in high demand by many patients.

Identification of a deletion variant in the gene encoding the human alpha(2A)-adrenergic receptor

OBJECTIVE

The alpha(2)-adrenergic receptors are involved in the effects of catecholamines on energy metabolism. Of three known subtypes with differential expression, alpha(2A)-adrenergic receptors are also localized in adipose tissue where they counteract the lipolytic activity of beta-adrenergic receptors. This study was undertaken to assess whether variants in the alpha(2A)-adrenergic receptor gene are associated with body weight.

DESIGN AND METHODS

Single strand conformation polymorphism (SSCP) screening and subsequent sequencing were applied to determine genetic variants in DNA samples from individuals with obesity, those of normal weight and those underweight.

RESULTS

Analysis of the coding region resulted in the identification of an 18 bp deletion, with no other mutation found. Of 429 genotyped subjects, 7 carried the deletion, with no significant differences between lean and obese subjects. A previously identified polymorphism in the promoter of the alpha(2A)-adrenergic receptor gene also did not show an association with any of the tested body weight categories.

CONCLUSION

Our data suggest that variants in the alpha(2A)-adrenergic receptor gene are unlikely to contribute to the predisposition for the lean or obese state.

Rates of psychiatric disorders in a clinical study group of adolescents with extreme obesity and in obese adolescents ascertained via a population based study

OBJECTIVE

To compare rates of DSM-IV psychiatric disorders between (1) a clinical study group of extremely obese adolescents and young adults, (2) gender-matched population-based obese controls and (3) a population-based control group of the same age range.

DESIGN

Rates of psychiatric disorders were assessed in (1) the clinical study group of obese adolescents and (2) the population based sample of obese adolescents, and compared to (3) a large population-based control group using a standardized psychiatric interview.

SUBJECTS

(1) Clinical study group: 30 female and 17 male extremely obese adolescents and young adults (age range: 15-21 y; mean BMI:42.4 kg/m2). (2) Thirty females and 17 males with the highest BMI (age range 15-21 y; mean BMI: 29.8 kg/m2) of a population-based control group encompassing 1655 (805 males) adolescents and young adults. (3) The population based control group excluding the 30 females and 17 males with the highest BMI (n = 1608; 788 males).

MEASUREMENTS

Munich-Composite International Diagnostic Interview (M-CIDI) allowing for DSM-IV diagnoses.

RESULTS

High rates of mood, anxiety, somatoform and eating disorders were detected in the clinical sample of obese adolescents which exceeded those observed in population controls (all P-values < 0.01). Rates between population-based obese adolescents and young adults and population controls did not differ. In most patients the psychiatric disorders set in after onset of obesity. 57% and 35% of the female and male patients, respectively, reported eating binges with lack of control. However, less than one-half of these patients qualified for a DSM-IV diagnosis of an eating disorder.

CONCLUSIONS

Extremely obese adolescents and young adults who seek long-term inpatient treatment have a high lifetime prevalence for affective, anxiety, somatoform and eating disorders. Because the mean BMI of the clinical study group was considerably higher than that of the obese population controls, we were not able to clarify whether the high rate of psychopathology in the study group was related to the extreme obesity or to their treatment-seeking behavior.

Independent confirmation of a major locus for obesity on chromosome 10

Linkage results obtained in genome-wide scans for complex phenotypes require confirmation in independent samples. Recently, linkage of obesity to chromosome 10p12 with a maximal multipoint LOD score of 4.85 was reported upon use of an affected sib-pair approach including nuclear families in which the adult index case had a BMI > or = 40 kg/m2 and at least one further sibling had a BMI > or = 27 kg/m2 (Hager et al., 1998, Nat Genet 20:304-8). To attempt to replicate this linkage finding we genotyped 11 markers spanning approximately 23 cM from 10p13 to 10ql1 in a total of 386 individuals stemming from 93 nuclear families with two or more young obese offspring with a BMI > or = 90th age percentile. The highest multipoint maximum likelihood binomial (MLB) LOD score using the extreme concordant sib-pair approach in which one sib had a BMI > or = 95th percentile, and other sibs a BMI > or = 90th percentile was 2.32. Six markers yielded nominal p-values < 0.05, the highest two point MLB-LOD score of 2.45 (nominal p = 0.0004) was obtained for the marker TCF8. Transmission disequilibrium tests for the most frequent parental allele yielded no nominal p-value < 0.05. The linkage results confirm the presence of a major susceptibility locus for obesity in a region near the centromere on chromosome 10.

Significant association between a silent polymorphism in the neuromedin B gene and body weight in German children and adolescents

Neuromedin B has been shown to exert an inhibiting effect on food consumption in rats. The corresponding gene NMB maps to chromosome 15q22.3-q23, a region expected to contain a gene for the Bardet-Biedl syndrome type 4 (BBS4). Based on its map position and the putative function of the encoded peptide, NMB can be considered as a candidate gene both for BBS4 and the development of human obesity. To examine its involvement in these phenotypes, we determined the genomic structure of human NMB, and performed a mutation screen in its coding region. In genomic DNA of six BBS4 patients and in a large population sample, two sequence variants were detected: a g.253C-->A transversion creating a P73T substitution and a g.401G-->A silent mutation changing the stop codon TGA into stop codon TAA. A case-control study with 92 extremely obese patients and 94 underweight students revealed a significant association between the g.401G-->A polymorphism and body weight (adjustedp = 0.03), which was confirmed in a validation sample consisting of 95 extremely obese patients, and 95 normal weight and 48 underweight individuals (Mann-Whitney p = 0.02). These results suggest a contribution of NMB or a gene in its close vicinity to genetic weight control in humans.

No evidence for involvement of polymorphisms of the dopamine D4 receptor gene in anorexia nervosa, underweight, and obesity

Family and twin studies suggest a genetic contribution to the etiology of anorexia nervosa (AN) and obesity. Genes involved in weight regulation can be considered as candidate genes for AN. The dopaminergic system has been implicated in weight regulation; previous results had suggested a possible involvement of the dopamine D4 receptor gene (DRD4). We screened for alleles of two different polymorphisms (13-bp deletion, 48-bp repeat) in the DRD4. For association tests, allele frequencies were compared between 109 inpatients with AN, 82 underweight students, and 327 extremely obese children and adolescents. For application of transmission disequlibrium tests (TDT) we additionally genotyped 57 and 137 trios comprising a patient with AN or an extremely obese child or adolescent, respectively, and both parents. All genotyping was performed with polymerase chain reaction fragment length polymorphism analyses. None of the association tests or TDT rendered nominal P values below 0.1. An influence of alleles of the DRD4 on the development of AN, underweight, or extreme early onset obesity was not detected. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:594-597, 1999.

No evidence for an involvement of alleles of polymorphisms in the serotonin1Dbeta and 7 receptor genes in obesity, underweight or anorexia nervosa

The serotonergic (5-hydroxytryptamine, 5-HT) system has been implicated in body weight regulation and in the etiology of anorexia nervosa (AN). Here we describe the screening of the known Phe-124-Cys polymorphism in the 5-HT1Dbeta receptor gene and of the known Pro-279-Leu polymorphism in the 5-HT7 receptor gene. For association tests allele frequencies were compared between up to 393 extremely obese children and adolescents, 142 underweight students and 84 patients with AN. None of the association tests revealed nominal P-values below 0.3. We conclude that a major role of the investigated polymorphisms in body weight regulation or AN appears unlikely.

Missense variants in the human peroxisome proliferator-activated receptor-gamma2 gene in lean and obese subjects

The peroxisome proliferator-activated receptor-gamma2 (PPARgamma2) is almost uniquely expressed in adipose tissue and is of major importance for fat cell differentiation and lipid metabolism. This study was undertaken to assess whether two missense variants in the PPARgamma2 gene are associated with early-onset obesity. A previously described polymorphism encoding for an amino acid exchange in codon 12 (Pro12Ala) was detected with allele frequencies of 0.13 in 296 markedly obese children and adolescents and 0.14 in 130 lean individuals. A Pro115Gln variant, which had been linked to obesity in Germans in a previous association study, was not detected in any of our obese or lean subjects, who are also of German origin. We conclude from our data that these two variants in the PPARgamma2 gene are unlikely to contribute to the high prevalence of early-onset obesity.

Several mutations in the melanocortin-4 receptor gene including a nonsense and a frameshift mutation associated with dominantly inherited obesity in humans

The melanocortin-4 receptor gene (MC4-R) has been implicated in weight regulation. Recently, two independent groups reported frameshift mutations associated with a dominant form of obesity (1, 2). We screened the coding region of the MC4-R in 306 extremely obese children and adolescents (mean body mass index: BMI 34.4 +/- 6.6 kg/m2), 25 healthy underweight students (mean BMI 17.1 +/- 0.8 kg/m2), 52 normal weight individuals (mean BMI 22.0 +/- 1.0 kg/m2), 51 inpatients with anorexia nervosa (AN, DSM IV criteria, mean BMI 14.3 +/- 1.5 kg/m2) and 27 patients with bulimia nervosa (BN, DSM IV criteria, mean BMI 21.7 +/- 5.8 kg/m2) by single strand conformation polymorphism analysis (SSCP). Several mutations were identified, including the frameshift mutation described (1). The mutations were as follows: a) The deletion of 4 bp (delta of CTCT at codon 211) results in a frameshift, thus rendering a truncated protein. This mutation has been assumed to be associated with dominantly-inherited morbid obesity in humans (1). Both the index patient (BMI 42.06 kg/m2, height 171 cm, age 19.6 years) and her mother (BMI 37.55 kg/m2, height 164 cm, age 42.5 years) were heterozygous for the deletion. b) A nonsense mutation at position 35 of the MC4-R was detected in two obese probands (BMI 31.29 kg/m2 and BMI 45.91 kg/m2). This mutation leads to a truncated protein that encompasses the N-terminal extracellular domain. Both carriers additionally showed (c) a missense mutation (Asp-37-Val). In both of these cases Tyr-35-Stop and Asp-37-Val were maternally transmitted, thus these variations form a haplotype. d) e) A male obese proband harbored two missense mutations (Ser-30-Phe, Gly-252-Ser). f)-i) Four different missense mutations (Pro-78-Leu, Thr-112-Met, Arg-165-Trp, Ile-317-Thr) were detected in four different male probands, respectively. All of these mutations (a to i) were found solely in extremely obese individuals whose BMIs were all above the 99th percentile. j) A silent mutation (C-579-T, Val-193-Val) was detected in a male underweight individual. k) A previously described polymorphism (Val-103-Ile; 3) was detected with similar frequencies in all different study groups. 1) We identified a novel polymorphism (Ile-251-Leu) with similar allele frequencies in all groups under study. In conclusion, our data indicate that mutations in the MC4-R are not uncommon. Whereas our data support the evidence for dominantly inherited obesity as revealed by the three obese probands with haplo-insufficiency, the functional significance of the missense mutations remains to be determined.

Systematic mutation screening of the estrogen receptor beta gene in probands of different weight extremes: identification of several genetic variants

Estrogens are known to have an inhibitory effect on food intake in rodents and primates. Decreased estrogen levels that are found for instance in menopausal woman and in ovarectomized rodents result in body weight gain. Estrogen can act both in the periphery and in the central nervous system via at least two different estrogen receptors (alpha and beta). We systematically screened the coding region and part of the 5' and 3'regions of the estrogen receptor beta gene (ER beta) in 96 extremely obese children and adolescents, 50 patients with anorexia nervosa (AN), 28 patients with bulimia nervosa (BN), and 25 healthy underweight individuals. We detected five different sequence variants in the ER beta: a) A 21 bp deletion (codons 238 to 244) was detected in two obese probands and an underweight individual. b) An 846G-->A transition leading to a nonconservative amino acid substitution (G-250-S) was found in two obese male probands. Both a) and b) were located within the flexible hinge region between DNA and ligand binding domain. c) For a 1082G-->A polymorphism we found suggestive evidence for an association between the more common 1082G-allele and anorexia nervosa (nominal p=0.04). d) One silent mutation (1421T-->C) was found solely in two obese probands. e) A common variant is located in the 3' nontranslated region at position 1730(A-->G). We did not detect association of this polymorphism to any of the analyzed phenotypes. We conclude that the ER beta harbors several different mutations and polymorphisms, none of which can readily be associated with the phenotypes under study.

Transmission disequilibrium and sequence variants at the leptin receptor gene in extremely obese German children and adolescents

Genetic determinants of the degree of obesity and body fat distribution have been demonstrated by family studies. The heritability has been estimated to be in the range 0.2-0.7. Mutation leading to obesity in humans has been described for only two genes, one of them the leptin gene. The leptin gene codes for a cytokine secreted by fat cells that binds to the leptin receptor (Lep-R), which exerts some of its biological functions by expression in the brain. Hence, the Lep-R gene appears to be a promising candidate for the determination of obesity in humans. We isolated genomic DNA clones from the Lep-R gene region and identified a new polymorphic microsatellite marker (OBR-CA) within 80 kb of the translation start of Lep-R. We genotyped this and a second, intragenic microsatellite marker (D1S2852) in 130 nuclear families consisting of extremely obese children and adolescents and both parents. Using the most frequent parental allele of both markers, our analysis revealed a significant transmission disequilibrium for the 266-bp allele of D1S2852 (corrected P-value=0.042). No significant result was obtained with the most frequent allele of OBR-CA (corrected P-value=1.0). However, two rare alleles showed transmission disequilibrium and were subsequently used for constructing a haplotype with the 266-bp allele. This haplotype had a transmission rate of 80% (nominal P-value=0.02). In order to identify the underlying mutation, we sequenced all coding exons of Lep-R and the partially overlapping gene encoding the obese receptor gene-related protein (ob-rgrp) in individuals carrying this haplotype. We found one new mutation (Ser675Thr) in the Lep-R gene in one proband and several other mutations known to be not associated with obesity in other study groups. As this new mutation cannot explain our positive linkage result, the transmission disequilibrium of the 266-bp allele and the high transmission rate of the identified haplotype point towards a mutation in close proximity to marker D1S2852.

No evidence for involvement of the leptin gene in anorexia nervosa, bulimia nervosa, underweight or early onset extreme obesity: identification of two novel mutations in the coding sequence and a novel polymorphism in the leptin gene linked upstream region

Mutations in the leptin gene can result in profound obesity in both rodents and humans. In humans, serum leptin levels correlate with body mass index (BMI: kg m(-2)). However, in patients with anorexia nervosa (AN) leptin levels are lower than in BMI-matched healthy controls. We had previously argued that genes involved in weight regulation should be considered as candidate genes for AN. To investigate this hypothesis we screened the coding region of the leptin gene and part of the leptin gene linked upstream region (LEGLUR) in 49 patients with AN and 315 children and adolescents with extreme obesity. Two novel mutations in the coding region (Ser-91-Ser; Glu-126-Gln), each found in a single proband, and a novel polymorphism in the LEGLUR (position -1387 G/A; frequency of both alleles approximately 0.50) were identified. Tests for association of LEGLUR polymorphism alleles were negative by comparing allele frequencies between 115 AN patients, 71 bulimia nervosa patients, 315 extremely obese children and adolescents, 141 healthy underweights and 50 controls that were not selected for body weight. Tests for transmission disequilibrium were also negative. Hence, an influence of variations in the leptin gene on eating disorders or extreme early onset obesity could not be detected.

Systematic mutation screening of the pro-opiomelanocortin gene: identification of several genetic variants including three different insertions, one nonsense and two missense point mutations in probands of different weight extremes

Pro-opiomelanocortin (POMC) is the precursor of melanocortins (adrenocorticotropin: ACTH, beta-endorphin, beta-lipotropin: beta-LPH, corticotropin like intermediate peptide, alpha-, beta- and gamma-melanocyte-stimulating hormone: alpha-, beta- and gamma-MSH) some of which act in the brain to reduce food intake and are potential mediators of leptin action. Recently, three different mutations in the POMC gene (POMC) were identified in two unrelated children that lead to early-onset extreme obesity, adrenal insufficiency, and red hair pigmentation. In the present study we systematically screened the coding region of POMC in 96 extremely obese children and adolescents, 60 healthy underweight individuals and 46 patients with anorexia nervosa (AN) and identified several variants. a) A 9 and an 18 base pair insertion (9bp and 18bp: AGC AGC GGC and AGC AGC GGC AGC AGC GGC, respectively, between codon 73 and 74; 1,2). These in-frame variants lead to the insertion of three or six amino acids (Ser-Ser-Gly; Ser-Ser-Gly-Ser-Ser-Gly) carboxy-terminal to gamma-MSH. Frequencies of the 9bp insertion allele varied between 3 and 5% among the different study groups (Pearson's chi2 P>0.5). b) Both an out-of-frame 6 bp insertion (within codon 176: GGG CCC) leading to the insertion of two amino acids (Arg-Ala) and a premature stop-codon (G-7316-T: Glu-180-Stop) within the gamma-LPH sequence were maternally inherited in an obese female proband. This proband inherited another missense mutation from her father (Glu-188-Gly). c) A missense mutation (G-7016-A; Asp-80-Asn) was observed in a single patient with AN who also harboured the 9bp insertion on a paternally derived haplotype. d) The allelic co-occurence of two silent mutations (C-6982-T and C-7285-T) was detected in two obese subjects. e) Two further silent mutations (C-3832-T; C-7111-G) were detected in an underweight and an obese subject, respectively. We conclude that the POMC gene harbors several different polymorphisms and mutations, none of which can readily be associated with the phenotypes under study.

Analysis of the uncoupling protein-1 (UCP1) gene in obese and lean subjects: identification of four amino acid variants

Uncoupling protein-1 (UCP1) is uniquely expressed in brown adipose tissue (BAT) and of major importance for the tissues thermogenic capacity. This study was undertaken to detect variants in the UCP1 gene by single strand conformational polymorphism (SSCP) analysis and subsequent sequencing, and determine their potential association with obesity. Four variants predicting for amino acid substitutions were detected, of which Arg40Trp (exon 1) and Lys257Arg (exon 5) were rare mutations. In contrast, the allele frequency of a polymorphism in exon 2 predicting for an Ala64Thr substitution was 8.2% in a cohort of 293 obese children and adolescents compared to 4.1% in 134 lean individuals, while the allele frequency of a Met229Leu variant (exon 5) was not markedly different between the obese (10.4%) and lean (12.0%) study groups. Although one of the identified polymorphisms tends to have a higher frequency in obese than in lean subjects, variants of the UCP1 gene do not seem to contribute significantly to the development of early-onset obesity in the German population.

Interactions between human bronchoepithelial cells and lung fibroblasts after ozone exposure in vitro

Long-term exposure to ozone has been shown to cause lung fibrosis and increased collagen synthesis by fibroblasts in experimental animals. As the bronchial epithelium appears to play a major regulatory role in inflammatory processes, we investigated whether ozone induces bronchoepithelial cells in vitro to increase gene expression of procollagens and other fibrogenic mediators in human lung fibroblasts. Membrane cultures of human airway epithelial cells (BEAS-2B) in the presence or absence of lung fibroblast (HFL-1) cultures were exposed to air or 500 ppb ozone for 1 h, followed by (co-)incubation periods of 11 and 23 h. After ozone exposure of the co-cultures, there were substantial increases of steady-state mRNA levels of both alpha1 procollagens type I and III as well as TGF beta1 in the fibroblasts above the corresponding air control levels. In the absence of ozone, the presence of epithelial cells always caused significant decreases in the basal steady-state mRNA levels of both procollagens as compared to their absence. There were no significant effects of ozone on the secretion or gene expression of TGF beta2, PDGF or IL-8 in any cell type. In contrast, co-culture condition induced altered patterns of IL-8 gene expression or of PDGF production in fibroblasts and bronchoepithelial cells, respectively, both in the absence or presence of ozone. In summary, our data demonstrate that the effect of ozone on fibroblasts was mediated by epithelial cells and that mutual regulatory interactions between the different cell types occur. Thus, our co-cultivation system in vitro appears to be able to mimic the in vivo situation providing insight into the nature of cellular interactions and modulation by ozone, which may occur in the whole organism after long-term exposure.

Screening for variability in the ciliary neurotrophic factor (CNTF) gene: no evidence for association with human obesity

Systemic administration of the neurocytokine ciliary neurotrophic factor (CNTF) normalizes the obese phenotype of ob/ob and db/db mice. CNTF exerts its multiple effects through a receptor complex whose sequence, localization in hypothalamic nuclei and mode of signal transduction share remarkable similarities with the leptin receptor. In the human CNTF gene, a mutation in the first intron creates a new splice acceptor site, with the resulting mRNA coding for an aberrant protein (Takahashi et al., 1994). Given the potential of CNTF to influence energy homeostasis, this study was undertaken to determine whether variability in the CNTF gene is associated with human obesity. The previously described mutation was found in 30.3% of obese children and adolescents, 7 of which were homozygous (allele frequency 0.163). 29.5% of lean subjects carried the mutation, none of which were homozygous (allele frequency 0.148; corrected p = 1 compared to obese). No further mutations were detected by single strand conformational polymorphism (SSCP) analysis. In conclusion, variants in the CNTF gene are unlikely to be associated with the development of early-onset obesity.

Screening for mutations in the neuropeptide Y Y5 receptor gene in cohorts belonging to different weight extremes

OBJECTIVE

The neuropeptide Y (NPY) Y5 receptor is presumed to be involved in the regulation of food intake.

DESIGN

To investigate the possible role of this receptor in weight regulation, the whole coding region of the NPY Y5 receptor gene was screened for mutations using temperature gradient gel electrophoresis (TGGE). Detected mutations were screened in extended cohorts. STUDY COHORTS AND METHODS: Cohorts of 87 extremely obese children and adolescents, 15 underweight subjects and 25 patients with anorexia nervosa (AN) were initially screened by TGGE. Extended samples of these cohorts (160 obese children and adolescents; mean body mass index (BMI) 33.5 +/- 6.4 kg/m2, 128 underweight subjects; mean BMI 18.4 +/- 1.0 kg/m2 and 58 patients with AN; mean BMI 14.6 +/- 1.7 kg/m2) were screened to determine the frequencies of a detected mutation and a detected polymorphism in the NPY Y5 receptor gene. In addition, a previously described polymorphism in the first intron of the NPY Y1 receptor gene was analysed.

RESULTS

The coding region of the NPY Y5 receptor gene encompasses one exon. A single mutation, which results in a non-conservative amino acid substitution in the first extracellular domain of the receptor (Glu-4-Ala), and one silent polymorphism (Gly-426-Gly-Gly) at nucleotide position 1278 (G-->A) were detected by TGGE. Both tests for association and linkage to the NPY Y1 and NPY Y5 receptor polymorphisms were negative among all cohorts. The Glu-4-Ala mutation was found only in a single patient with AN and her mother.

CONCLUSION

The results do not support a major role of the NPY Y5 receptor gene in the variability of body weight in children and adolescents.

Further support for linkage of extreme obesity to the obese gene in a study group of obese children and adolescents

The role of the obese gene in human obesity is presently unclear. Evidence for linkage of markers flanking the gene to obesity has been found in some but not all studies. We investigated transmission disequilibrium between two highly polymorphic microsatellite markers (D7S504 and D7S1875) flanking the human obese gene (OB) and extreme obesity in a study group of German children and adolescents. Due to the early onset and severity of obesity in the ob/ob mouse we hypothesized that especially children and adolescents with extreme obesity are enriched for possible mutations in the human OB. The analysis of 88 trios (index probands and both parents) for transmission disequilibrium of a haplotype which has previously been determined to be linked to extreme obesity (Reed et al., 1996) revealed a one-sided transmission disequilibrium test (TDT) p-value of 0.039. Post hoc analyses revealed one-sided TDT p-values of 0.015 for the 214 bp allele of D7S1875 (corrected p-value = 0.03) and 0.215 for the 145 bp allele of D7S504 (corrected p-value = 0.43). These findings substantiate the evidence for linkage of extreme obesity to OB.

Obstructive sleep apnoea and diabetes mellitus: the role of cardiovascular autonomic neuropathy

Knowledge of conditions associated with an increased prevalence of obstructive sleep apnoea (OSA) may help to identify patients with OSA and might give some insight into the pathogenesis of OSA and its sequelae. A number of earlier, smaller studies hinted at an association between diabetic cardiovascular autonomic neuropathy (AN) and OSA. The present study was, therefore, conducted with the aim of establishing the prevalence of OSA in diabetics with AN and of determining whether OSA is more prevalent in diabetics with AN, than in those without. We studied two groups of diabetic patients: 23 with and 25 without AN. All patients were evaluated for possible OSA (apnoea/hypopnoea index > or = 10) using initial ambulatory screening followed by polysomnography. Six patients with AN (26%) were found to have OSA, but none of the patients without AN met the diagnostic criteria (p<0.01). When the patients with OSA were compared to those without, no differences were found in terms of age, sex, body mass index or diabetes type or duration. In conclusion, about one in four diabetic patients with autonomic neuropathy suffers from OSA. Thus, obstructive sleep apnoea is more prevalent in diabetic patients with autonomic neuropathy, than in those without.

[Changes in regional CNS perfusion in obstructive sleep apnea syndrome: initial SPECT studies with injected nocturnal 99mTc-HMPAO]

Some of the clinical features of obstructive sleep apnoea syndrome (OSA) are suggestive of impaired cerebral blood flow. Cerebral blood flow alterations might, for example, be responsible for headaches, which are frequent complaints in patients with OSA. Even the high frequency of ischaemic cerebral complications in patients with OSA might be caused in part by sleep apnoea-associated impairment of cerebral perfusion. Previous studies have demonstrated reduced total cerebral blood flow in patients with OSA, but regional changes of cerebral perfusion have not been studied up to now. We performed SPECT studies using 99mTc-(d,l)-hexamethyl-propylenaminoxim (HMPAO) as a tracer in 14 adult patients with moderate to severe OSA (AHI > 30/h; mean AHI 59.2 +/- 4.3). The injection of the tracer took place between 2:00 and 4:00 a.m. while repeated episodes of obstructive apnoea were detected by polysomnography during stage II sleep. Data acquisition took place at 7:30 a.m. All measurements were repeated some nights later under effective treatment with nCPAP. Visual analysis showed marked frontal hyperperfusion in 5 patients. When regional perfusion indices were calculated for 32 regions of interest statistical analysis showed reduced perfusion of the left parietal region. These changes were completely reversed by effective nCPAP therapy. These data suggest that OSA is associated with reversible changes of regional cerebral perfusion. The underlying pathophysiologic mechanisms are matter of speculation so far. There might be an apnoea-associated effect of local vascular autoregulation mechanisms acting to compensate systemic blood flow alterations or blood gas changes in OSA. The observed frontal hyperperfusion might be caused by activation of the frontal lobe by repetitive cortical arousals.

'Functional relaxation' reduces acute airway obstruction in asthmatics as effectively as inhaled terbutaline

BACKGROUND

'Functional relaxation' (German: 'Funktionelle Entspannung') has been developed since 1944 by the German physiotherapist M. Fuchs. It is based on concentrating on body perception while moving the joints of the skeleton smoothly and at the same time breathing out. This procedure induces a physical and emotional relaxation in many cases. The aim of the study was to compare the efficiency of standardized elements of a somatopsychotherapy (eFE) and a standardized bronchodilatative test using terbutaline (IT).

METHODS

Seventeen asthmatic patients with acute airway obstruction had either IT or eFE on 2 consecutive days. Airway resistance (R(aw)) was measured before and after IT and eFE. It was used for statistical evaluation as it is independent of the patient's will.

RESULTS

Although both therapies lead to a significant mean decrease in R(aw) (p < 0.01), the comparison revealed no superiority of one over the other (ANOVA on repeated measurements, p > 0.78).

CONCLUSIONS

This study supports the benefit of psychosomatic therapy in the relief of asthma and the procedure can be used as an easy-to-learn relaxation technique to be used during acute asthmatic airway obstruction.

Polarity of secretion of alpha 1-antitrypsin by human respiratory epithelial cells after adenoviral transfer of a human alpha 1-antitrypsin cDNA

alpha 1-Antitrypsin (alpha AT) deficiency, a hereditary cause of progressive emphysema, can potentially be treated by transfer of a functional human alpha 1AT gene to the respiratory epithelium. For such an approach to be successful, alpha 1AT must be provided to both the interstitium and the epithelial surface--that is, the alpha 1AT directed by the transferred gene must be secreted to both the apical and basolateral surfaces of the epithelial cells. To evaluate this concept, a recombinant, replication-deficient adenoviral vector (Ad-alpha 1AT) containing a human alpha 1AT cDNA driven by an adenovirus major late promoter was used to infect Bet-1A human respiratory epithelial cells. The infected cells expressed Ad-alpha 1AT-directed mRNA transcripts and synthesized and secreted functional human alpha 1AT as shown by [35S]methionine labeling and immunoprecipitation of a 52-kD glycosylated human alpha 1AT molecule capable of interacting with neutrophil elastase, its natural substrate. Bet-1A cells grown on microporous polycarbonate membranes formed tight junctions (resistance > 150 omega x cm2). After infection with Ad-alpha 1AT, [35S]methionine labeling and enzyme-linked immunoassay demonstrated that alpha 1AT was secreted into both the apical and basolateral compartments, with an average apical to basolateral ratio of 1.9 +/- 0.2. Thus, human respiratory epithelial cells infected with a recombinant adenoviral vector containing a human alpha 1AT cDNA secrete alpha 1AT across both the apical and basolateral cell membranes, suggesting that the respiratory epithelium could serve as a target for in vivo gene therapy of alpha 1AT deficiency.

[Effect of a filter system on measurement data and bacterial contamination in lung function studies]

80 measurements of the airway resistance of 20 patients did not yield any significant differences with or without using a bacterial filter (Pall PF 30) (p = 0.1213). Likewise, lung function tests conducted in 61 further patients did not reveal any relevant changes caused by introducing the filter, in respect of the lung function parameters VKin, FEV1, PEF, FEF25, FEF50, FEF75 and TLCO. In these studies the flow receptors were examined for contamination by bacteria. The introduction of the bacterial filter reduced the total count of identified germs from 108, 615 to 307, i.e. by 99.7 per cent, the greatest contamination being found in those parts that were close to the patient (57.6% with filter, 97.1% without filter). Germs of the resident flora of the mouth and pharynx were identified, and occasionally also potential infectious agents such as staphylococcus aureus and streptococcus pneumoniae. The use of a filter system results in a marked decrease in the exposition to germs in lung function tests, without exercising any adverse effect on the measurement data (cross-contamination risk: 0.00078%). This is also achieved--albeit to a lesser extent--by changing those parts of the flow receptor that are close to the patient (cross-contamination risk: 0.0841%). Hence, the use of a filter system appears particularly meaningful in patients with considerable immunodeficiency (advanced stages of HIV infection).

Adenovirus-mediated transfer of a recombinant alpha 1-antitrypsin gene to the lung epithelium in vivo

The respiratory epithelium is a potential site for somatic gene therapy for the common hereditary disorders alpha 1-antitrypsin (alpha 1AT) deficiency and cystic fibrosis. A replication-deficient adenoviral vector (Ad-alpha 1AT) containing an adenovirus major late promoter and a recombinant human alpha 1AT gene was used to infect epithelial cells of the cotton rat respiratory tract in vitro and in vivo. Freshly isolated tracheobronchial epithelial cells infected with Ad-alpha 1AT contained human alpha 1AT messenger RNA transcripts and synthesized and secreted human alpha 1AT. After in vivo intratracheal administration of Ad-alpha 1AT to these rats, human alpha 1AT messenger RNA was observed in the respiratory epithelium, human alpha 1AT was synthesized and secreted by lung tissue, and human alpha 1AT was detected in the epithelial lining fluid for at least 1 week.

[Metastatic basal cell carcinoma]

One day before his death, a 66-year-old man who had been suffering since childhood from a severely itching and repeatedly bleeding skin lesion was examined for the first time by a general practitioner who immediately advised hospitalization. On admission, an extensive rodent ulcer on his back was noted and septic shock diagnosed. Because of the hopeless diagnosis no life-supporting measures were undertaken. Postmortem examination revealed an 18 x 26 cm sized ulcerating basal cell carcinoma on the back with infiltration of the thoracic vertebrae and a fist-sized paravertebral abscess between the left upper and lower lobe of the lung and abscessing pneumonia. Two metastases each were found in the right lung and in both kidneys with the histologically characteristic picture of basal cell carcinoma. This case confirms the observation that this type of carcinoma has the potential for metastasizing, but it usually does not do so because of its biological characteristics and early curative excision.

The diagnostic validity of the serum tumor marker phosphohexose isomerase (PHI) in patients with gastrointestinal, kidney, and breast cancer

The diagnostic validity of the glycolytic enzyme phosphohexose isomerase (PHI) as a serum tumor marker was evaluated. For this purpose the sensitivity of PHI was determined in 435 patients with histopathologically defined, malignant gastrointestinal, kidney, and mammary tumors prior to primary treatment. To assess the specificity, PHI serum activities were measured in 181 patients with benign diseases and disorders from an internal practice. In gastrointestinal and kidney cancer, PHI reached an overall diagnostic sensitivity of about 70%, and a specificity of 92% was obtained. Even in early stages without metastasis, elevated PHI serum levels were found in about 60% of the patients. In mammary cancer, however, a sensitivity of only 40% was observed. PHI activity can be measured without the need for highly technical skills and equipment, in a short time and at low cost. These data suggest that serum PHI can be a useful indicator in the preventive checkup of gastrointestinal and renal cancer in medical practice.

Levels of 5'-nucleotide phosphodiesterase isoenzymes in normal and pathological sera

The levels of 5'-nucleotide phosphodiesterase isoenzymes (5'-NPD; EC 3.1.4.1) in sera of 54 healthy donors and 201 inpatients were measured. Isozymes were separated electrophoretically and designated as 5'-NPD-0, -I, -II, -III, -IV and -V in the reverse order of their electrophoretic mobility. In healthy donors all isozymes except 5'-NPD-V were detectable. In pathological sera isozymes 0 to V were elevated in 26.0%, 20.5%, 14.0%, 30.5%, 7.0% and 15.0% of the cases, respectively. Decreased values were found in 6-7%, with the exception of 5'-NPD-IV showing decreased activities in 23.5% of the patients. This average distribution pattern was found in many disorders. However, in diseases of the liver and the pancreas a remarkable accumulation of cases with elevated levels of all isozymes, except 5'-NPD-IV, was observed. All isozymes, except 5'-NPD-IV, showed many significant correlations with other laboratory parameters indicating liver disease. Isozyme IV was not related to these parameters but exhibited a strong correlation with serum albumin. 5'-NPD-II was unproportionally often increased in patients with liver cirrhosis and was the only isozyme with on the average higher levels in women than in men.

Catalytic activity concentrations of diadenosine tetraphosphate hydrolase in normal and pathological sera

The levels of diadenosine tetraphosphate hydrolase, a nucleotide pyrophosphatase (EC 3.6.1.9), were measured in human sera with a bioluminescence method. 40 sera of healthy donors and 207 samples obtained from inpatients of a medical clinic were analysed. About two thirds of the patients showed increased hydrolase levels, as compared to the normal donors. Elevated levels were not specific for a certain disease, and they were found in quite different disorders. There was no indication for a dependency of enzyme activity on age or sex of the patients. The comparison of diadenosine tetraphosphate hydrolase with seven other laboratory parameters revealed a highly significant correlation with gamma-glutamyl transferase, suggesting that the liver may be a source of elevated serum activities. There was evidence that the gastrointestinal tract and the pancreas may also be regarded as possible organ sources of the hydrolase.

[Comparison of CA 50 and CA 19-9 tumor markers in benign and malignant diseases of the upper gastrointestinal tract]

Tumour-associated antigens CA 50 and CA 19-9 were determined in serum of 208 patients. Specificity of both neo-antigens as tumour markers was equally good, at 100% and 95%, in patients without malignancy or gastrointestinal disease, respectively, using an upper limit of normal of 17 U/ml for CA 50 and 37 U/ml for CA 19-9. Benign diseases of the upper gastrointestinal tract, such as pancreatitis, cholestasis or cirrhosis of the liver, reduce the specificity of CA 50 more than of CA 19-9. For example, specificity of CA 50 is only 33% for choledocholithiasis, but 74% with CA 19-9. The sensitivity of both closely related sialogangliosides in malignancies of the upper GI tract is similar, with the usual normal limits: in pancreas carcinoma 77% for CA 50, 81% for CA 19-9; in biliary tract carcinoma 80% for CA 50, 90% for CA 19-9; in gastric carcinoma 40% for CA 50, 50% for CA 19-9. But if one equalizes the upper limits of normal for both markers to a common 95% specificity, the tumour-indicating sensitivity of CA 19-9 clearly surpasses that of CA 50. Malignant tumours not recognized by increased levels of CA 19-9 also escape serological diagnosis with CA 50.